The laying of sewage and water pipes commonly calls for the excavation of trenches. Traditionally, a trench is dug in twenty-foot (20') sections, that being the usual length of pipe sections, and the dirt is stacked on one or both sides of the trench as bedding is added and the pipe laid down. More bedding is added on top of the pipe, the removed soil is added as fill, packed down and the work is moved on to the following second twenty-foot (20'). Frequently, the excavation of such trenches occurs in laterally confined spaces, such as alleyways or medians in a road. Such lateral confinement creates a number of problems, one of which is where to put the excavated soil. There may be very little room on either side of the trench to lay the removed soil.
The problems created by stacking the removed soil in or near the trench site include damage to fencing and walls on private property as the dirt is dumped to either side of the trench. Moreover, the confined space makes it more dangerous for the workers to lay the pipe and grade the bedding, and to operate the backhoe and other machinery in and around the trench. As a result of such problems, trenching in confined areas is a slow, laborious, and expensive process, little improved in the last 30 years.
U.S. Pat. No. 3,842,994 (Theurer et al. 1974) discloses a train of freight cars with each car consisting of a storage bin with a top opening. An adjustable conveyer belt is located above each bin belt connecting it to the next bin. The belts are adjustable in height to carry rubble from an excavation site to the bin.
U.S. Pat. No. 850,107 (Wolever 1907) discloses a series of endless conveyer belt sections designed to convey articles from a sending station to a receiving station, wherein each section is attached to an adjacent section by using an adjustable swinging gate.
U.S. Pat. No. 236,192 (Stillman 1881) discloses an apparatus for conveying and distributing soil which consists of a series of endless belts arranged to receive material at one end to carry and deliver to the other end; the belts are connected to gates and pulleys to adjustably control the operation of the belts of a given section.
U.S. Pat. No. 4,256,213 (Shaw et al. 1981) discloses a flexible, mobile conveyer system comprised of a series of conveyer tracks connected at adjustable joints, which device is particularly useful in deep mining operations.
U.S. Pat. No. 2,479,823 (Ernst 1949) discloses a plural conveyer arrangement which includes a pivoting means for connecting two or more conveyers so that articles can be carried in angled directions should straight line conveyance not be feasible or desired. The conveyor units are not only pivoted together for angled-directional carriage of articles, but also expansible and contractible, making it possible to connect a loading platform with a specific station within a reasonable distance.
U.S. Pat. No. 3,251,449 (Hoppmann 1966) discloses a loading device which contains a reversible belt conveyer, which device can be raised and lowered with respect to a second conveyer.
However, none of the prior devices or methods address or solve the problems of working in a laterally confined space. These problems applicant solves by using an apparatus comprising a train of at least two endless, reversible conveyer sections linked by a pivoting means for connecting the sections so that soil can be carried an angled direction should straight line conveyance not be feasible. The pivoting means or swivel connection admits universal movement and allows for the removal of soil from a loading station to a receiving station and upon reversal of the belt conveyers and selectively changing the height of the belts, transporting bedding and fill from the receiving station to a filling station, including means for delivery to the area between the conveyer sections, from either end.
The present invention relates to means for and a method of excavating the spoil, laying bedding, "select material" and backfill, which apparatus method avoids the problems set forth above.
It is the purpose of the present invention to provide a means for facilitating the excavating and refilling of a trench, which means includes alternately removing spoil to create a trench, adding pipe, bedding, select material and backfill, repeated in sequence, using an apparatus which contains at least two longitudinal sections supported on trucks and linked at a universal pivot point, each section containing a reversible endless conveyer belt for alternately removing and adding material to and from the work site.
It is a further object of this invention to provide for an apparatus and method which includes a method for alternately removing and refilling dirt from a trench, which apparatus straddles the trench and consists of at least two conveyer belt sections, which apparatus carries material to and from the trench and moves longitudinally as the trench is excavated at one end and refilled at the other, which excavation and refill alternates with the laying of pipe sections.
It is a further object of the present invention to provide for an apparatus for aiding the excavation and filling of trenches in laterally confined areas, the apparatus comprising a first and a second conveyer section, each conveyer section having an endless belt, a belt drive means for energizing the conveyer belt, a means for connecting the two conveyer belt sections, which means can selectively position the adjacent conveyer means, one above the other, while at the same time allowing one section to pivot horizontally with respect to the other.
It is a further object of the present invention to provide for an apparatus which contains two units or sections, each having a conveyor belt, which sections meet at an attachment point, which point allows material carried on the conveyor belt of either section to be deposited at the junction of the two sections.
It is a further object of the present invention to provide for a two-section conveyor apparatus wherein each unit contains an endless, reversible conveyor belt and which units are attached such that adjacent ends may be raised, one above the other, for selectively carrying material from one end of the apparatus to the other, or depositing such material at the joint where the two sections meet.
Further objects of this invention will be apparent upon references to the following claims and specifications.